Avalanche Forecast

Issued: Dec 18th, 2011 8:55AM

The alpine rating is moderate, the treeline rating is moderate, and the below treeline rating is low. Known problems include Wind Slabs.

jfloyer, Avalanche Canada

South Rockies.

Summary

Confidence

Good - -1

Weather Forecast

Monday: Dry and bright. Treeline temps around -8C. An inversion will push alpine temps to around -2C. Moderate northwesterly winds. Tuesday: Light snow – around 3cm with strong northwesterly winds. Alpine temps falling to -12C by the end of the day. Wednesday: Flurries. Light to moderate northerly winds. Alpine temps around -18C.

Avalanche Summary

Small point releases to size 1 were noted from an area east of Hwy 43 in steep terrain. Recent reports of riders triggering small wind slabs on NE aspects around 2100 m are now a few days old, but still valid, given the recent wind event.

Snowpack Summary

A significant wind event on Saturday redistributed snow, scouring west-facing slopes and depositing highly variable wind slabs on east-facing slopes. A buried layer of surface hoar lies approximately 20 cm below the snow surface. Reports indicate this layer was blown around before it was buried and can only be found in isolated, sheltered locations. A well settled mid pack bridges over the basal weaknesses at the ground. The crust/facet combo still exists at the ground. This layer was responsible for some large releases earlier on in the season. However, there hasn't been any activity on this layer since early December and confidence is growing that it is gaining strength.

Problems

Wind Slabs

Shifting winds have set up wind slabs on a variety of aspects, particularly north through southeast. Cross-loading is also possible on open slopes generally oriented parallel to the wind, which contain features and gullies to catch wind-drifted snow.

Aspects: North, North East, East, South East, South.

Elevations: Alpine, Treeline.

Likelihood

Possible - Likely

Expected Size

1 - 3

Valid until: Dec 19th, 2011 8:00AM